Field of the Invention
The present invention relates to a container treatment plant and method for displacing an element of a valve or a diverting unit of a container treatment plant.
Description of the Prior Art
In a container treatment plant, a plurality of containers are transported between different container treatment stations, like a stretch blow molding machine, a labeling unit, an inspection unit, a filling unit, a cleaning unit, etc. by using one or more different transporting unit(s). The containers are treated in the different container treatment stations by the use of valves, like blowing valve, filling valve, etc., and/or diverting units, like pusher, hedgehog, etc.
Valves and diverting units each comprise an element that is to be displaced between a first position and a second position. Concerning a valve, the element is to be moved between an opened position and closed position, which are the both end positions, of the valve. Herein, also intermediate positions located between the both end positions shall be possible if necessary. In the diverting unit, the element is to be moved between a first position, in which no diversion of the container takes place, and a second position causing the diversion of the container. Where required, intermediate positions shall be possible between the both positions, as well. With current valves and diverting units, usually, only two positions like open/closed are possible, but no intermediate positions are possible therebetween. Currently, intermediate positions can be realized only by an additional mechanically displaceable stop, which is intricate and thus expensive.
It is further problematic that the displacement of the elements of the valves and diverting units has to be effected adapted to a production speed of the container treatment plant of, for example, up to 40,000 containers per hour or a speed of the containers of approximately 2 m per second. Thus, the displacement of the valves and diverting units has to be effected very fast and further also very precise to cause no plant down time. Plants down times bring about losses of production and require the use of operating personal so that the production costs augment.
For the displacement of the valves and diverting units in such a container treatment plant are used so far different mechanisms which are operated by compressed air, where required. The mechanisms are depending on the construction liable to wear and thus maintenance-intensive. There is a significant diversity of the switching time of presently +/−2 msec as regards the valves and diverting units. Because of this, more control air is necessary so that consumption of compressed air increases. However, compressed air is comparably expensive. Moreover, the response times of the valves and diverting units are longer than desired because of a switching edge until the increase of the pressure.